Seat belt buckle

ABSTRACT

A seat belt buckle of the push button type wherein a lever member is pivoted intermediate its ends within the buckle housing with one end of the lever underlying an opening in the top wall of the housing to permit engagement of that end of the lever by the finger of an operator, while the other end of the lever defines a detent structure which releasably engages the tip end or blade of the mating belt assembly.

United States Patent 72] Inventor William V. Bachmann St. Clair Shores, Mich. ll I Appl No 841,334 i221 Filed July 14. 1969 {45 i Patented Aug. 24, 1971 3] Assignee Chrysler Corporation Highland Park, Mich.

' i 54] SEAT BELT BUCKLE 10 Claims, 5 Drawing Fig 152] U.S.Cl. 24/230A [51] lnt.Cl ..A44b 11/26 {50] Field of Search 24/230 A i (a 5 References Cited UNITED STATES PATENTS HJQIOIO 5/ I963 24/230 A UX 3,165,806 1/1965 Lehman 24/230AUX 3,203,064 8/1965 Murphy 24/230AUX 3,453,699 7/1969 Smith 24/23OAUX 3,494,007 2/1970 Dahms 24/230AUX Primary Examiner-Bernard A. Gelak An0rneyHarness, Talburtt and Baldwin ABSTRACT: A seat belt buckle of the push button type wherein a lever member is pivoted intermediate its ends within the buckle housing with one end of the lever underlying an opening in the top wall of the housing to permit engagement of that end of the lever by the finger of an operator, while the other end of the lever defines a detent structure which releasably engages the tip end or blade of the mating belt assembly.

SEAT BELT BUCKLE BACKGROUND OF INVENTION This invention relates to seat belt buckles, and more particularly, to seat belt buckles of the push button type. Many forms of push button seat belt buckles are presently available and/or in actual use. While these available buckles are generally satisfactory, their construction is rather complex with the result that they are expensive to manufacture, and at least in some forms, have a relatively high operator effort requirement under certain load conditions.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a seat belt buckle of the push button type which is simpler in construction than the known types.

A more specific object is to provide a push button seat belt buckle which is less expensive to manufacture than known types.

Another object is to provide a push button seat belt buckle having an exceptionally low operator effort requirement with the buckle under load.

In the seat belt buckle of the invention, a lever is pivoted intermediate its ends within a hollow buckle housing assembly for pivotal movement about a generally horizontal axis. One end of the lever is provided with a detent structure and the buckle housing includes a horizontal slot at the end of the housing adjacent the detented lever end for passage of the tip end of the mating belt assembly for coaction with the lever detent structure. Means are provided on the top wall of the housing which define a lever actuator area overlying the other end of the lever to permit depression of that lever end to release the detented end of the lever from the tip end.

Means are provided within the housing which operate as the tip end is inserted into the housing to its detented position to guide the tip end into an orientation within the housing wherein the line of action through the tip end passes above the pivot axis of the lever. These guide means may comprise a ramp surface which angles upwardly relative to the general plane of the bottom wall of the housing and operates as the tip end is inserted to guide the tip end into an upwardly angled orientation. The ramp surface may be provided, for example, as the angled upper surface of an insert member positioned within the housing adjacent the entry end of the housing.

Other objects and features of the invention will be apparent from the detailed description of the preferred embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS The preferred embodiment of the invention is illustrated in the drawings, in which:

FIG. 1 is a fragmentary top view of a push button seat belt buckle according to the invention;

FIGS. 2 and 3 are cross sectional views taken on line 2-2 and 3-3, respectively, of FIG. 2;

FIG. 4 is a perspective view of a subassembly of the invention buckle; and

FIG. 5 is a fragmentary view looking in the direction of the arrow Sin FIG. 1

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The buckle of the invention, broadly considered, includes a housing assembly and an actuator assembly positioned within the housing assembly.

The housing assembly includes a steel base or frame member and a molded cover member 12 of suitable plastics material such, for example, as ABS plastic. Base member 10 is fonned as a stamping, and includes a bottom wall 14 and an upturned sidewall 16, 18 at either longitudinal edge of bottom wall 14. Bottom wall 14 has a relatively wide rear portion 14a of generally uniform width and a trapezoidal front portion 14b tapering toward the front of the buckle. Sidewalls 16, 18 follow the side edge contour of bottom wall 14.

Cover member 12 is designed to fit over base member 10 and includes a top wall 20, forward and rearward end walls 22, 24, and sidewalls 26, 28.

An actuating lever 30 is pivoted intermediate its ends within the housing assembly defined by base member 10 and cover member 12. The rear or actuator end 30a of lever 30 defines at its upper surface a large area, flat pressure surface 30b, and the forward lever end 30c is configured to define a detent structure. Means are provided on cover top wall 20 which define a buckle actuator area overlying the actuator end 30a of the lever to permit depression of that end to operate the detent structure at the other end of the lever. In the disclosed embodiment, these means comprise a generally circular opening 20a in cover top wall 20 overlying lever pressure surface 30b. Detent lever end 300 includes a central portion which is struck out of the surrounding material and depressed downwardly to define a detent lip or edge 30d for latching coaction with the forward edge 32 of an aperture 34 in the tip end 36 of the coacting belt half assembly. Lever 30 further includes downwardly turned ears 30e passing a pivot bar 38 to define the pivot axis for the lever.

Pivot bar 38 has an angular cross section and may be formed of a suitable metal in an extrusion process; bar 38 includes a generally downwardly oriented leg portion 38a and a generally horizontally and forwardly extending leg portion 38b. The ends of bar 38 are slideably received in angular slots 40 in base sidewalls 16, 18. Openings 42 in ear 30e receive bar 38; openings 42 are oversize with respect to bar 38 to allow limited rocking movement of lever 30 on bar 38'with the rocking fulcrum located at the lower edge38c of bar portion 38a and the relative movement of the bar and lever occuring as pivotal or rocking movement of the rear corner edge 42a of opening 42 on lower bar edge 38a. The ends of bar 38 are cut at an angle to match the forwardly tapering angle of base sidewalls l6, l8 and the bar is held in position by cover sidewalls 26, 28. The forwardly extending leg portion 38b of bar 38 coacts with a ramp insert 44 to guide the entry movement of tip end 36 and trap the tip end in its buckled position.

Ramp insert 44, as seen in isolated perspective in FIG. 4 and in assembled relation in FIGS. 1, 2 and 3, is preferably molded of a suitable plastics material such, for example, as Nylon. Insert 44 includes a central, generally trapezoidal portion 44a flanked by generally triangular outrigger portions 44b separated from main body portion 44a by bias grooves 440. In assembled relation, insert 44 is positioned on base bottom portion 14b with a lip 44d at the forward lower edge of the insert engaging the forward edge of bottom portion 14b and a nib 45 struck upwardly from bottom portion 14b seating in a pocket 442 in the lower face of insert central portion 44a. The upper face 44 f of central portion 44a defines a ramp surface for guiding the entry movement of tip 36 through an entry slot 46 defined between the forward end of ramp surface 44f and the lower edge 22a of cover forward wall 22.

The rear end of ramp insert 44a is pressed firmly against base bottom wall 14b by the seating engagement of edge 38c of bar 38 in a shallow groove 44g extending across the rearward tip of insert central portion 44a. The forward end of ramp insert 44 is clamped against base bottom wall 14b by the forwardly extending legs 47a of a wire spring 40 formed of spring steel; spring legs 470 are received in and extend along bias grooves 44c. The central or bight portion 47b of spring 47 bears upwardly against lever end 30a to continually bias the lever toward its solid line position of FIG. 2. Spring leg portions 470 are joined to bight portion 47b by knee portions 470 bearing downwardly against the adjacent portion of base bottom wall 14b. A crank portion 47d at the forward end of each spring leg 47a is bent outwardly to seat in a notch 16a, 18a in the forward lower end of the adjacent base sidewall; a forwardly angled spring portion 47e is provided at the outboard end of each crank portion 47d and each portion 47e is in turn bent over to terminate in a downwardly angled spring portion 47f. Spring portions 47e, 47f will be seen to together define generally hook shaped members for coaction with generally hook shaped pockets 49 molded into cover sidewalls 26, 28. When assembling the cover member to thebase member, hook shaped pockets 49 are fitted with a cocking action over the hook shaped spring ends to position spring portion 47e, 47f within the cover pockets; the cover member is then pivoted downwardly about the torsion axis of spring crank portion 47d to snap a pair of tabs 24a on cover'rear wall 24 over lips 16b, 18b formed by cutouts 16c, 18c at the lower rear edge of each base sidewall 16, 18. As the cover member is rotated into position on the base, spring portions 47e are moved from their forwardly angled unloaded positions of FIG. 4 to their generally vertical loaded positions of FIG. 5; this rotary movement causes spring positions 47d to act as torsion bars which are thus loaded to firmly press spring legs 47a downwardly in clamping relation against insert 44. Spring 47 thus serves to provide spring loading for lever 30, preclude upward movement of the forward end of the ramp insert, and resist displacement of the forward end of the cover member relative to the base member.

The buckle assembly is completed by the usual knurled bar 48 having flat bar ends 50 slideably received in slots 52 in base sidewalls 1 6, 18; a belt loop 54 passes through an opening 56 in base bottom wall 14 and wraps in known manner around bar 48 to secure the belt to the buckle.

OPERATION OF THE PREFERRED EMBODIMENT Spring 46 normally maintains lever 30 in the solid line position of FIG. 2 in which pressure surface 30a is disposed immediately below cover opening 200 and detent edge 30d is disposed in juxtaposition to ramp surface 44f, this position is limited and determined by the abutting engagement of the upper edges 42b of apertures 42 with the upper edge 38d of bar leg portion 38b. To buckle the'two belt halves together, tip end 36 is inserted through slot 46 and guides up ramp surface 44f into the pocket defined between bar leg portion 38b and the rear portion of the ramp surface. As tip 36 moves up the ramp it cams detent 30c upwardly against the bias of spring 47 until tip edge 32 clears detent edge 30d, whereupon spring 46 returns lever 30 to its solid line position with edges 30d and 32 in confronting, abutting engagement to preclude withdrawal of tip end 36. This buckled position of tip end 36 is seen in dotted lines in FIG. 2;,in this position, the leading edge of tip end 36 is trapped in the pocket between ramp 44f and bar portion 38b so that tip end 36 is precluded from any upward tilting movement that could have the effect of tilting lever end 30c upwardly out of detenting engagement with tip edge 32. The inserting movement of tip 36 up the ramp surface is limited by engagement of shoulders 36a on the tip end with forward edges portions 16d, 18d of base sidewalls 16, 18.

To release tip end 36, the actuator end 30a of lever 30 is depressed by an operator's finger tip inserted through cover opening 20a: downward movement of actuator end 30a raises detent end 300 to release tip end 36 and allow it to be withdrawn, whereafter actuator end 30a may be released to allow spring 47 to return lever 30 to its solid line position. During the releasing movement of lever 30, corner edges 42a of lever apertures 42 rock on the bar lower edge 38a with the extent of rocking movement being determined and limited by engagement of lower aperture edges 42c with the lower edge 38 of bar leg portion 38b. This released lever position, including the position of apertures 42 relative to bar 38, is seen in dotted lines in FIG. 2. When the buckle in its buckled condition is subjected to'a load, as for example in the case of an accident, tip end 36 transmits a load to lever 30 through abutting edges 30d, 32 with the line of action of the load generally approximating the angle of ramp surface 44f; since this line of action passes above the point of rocking engagement of aperture corners 42a with bar edge 38a, the transmitted load generates a force component tending to rock lever 30 clockwise as viewed in FIG. 2 to ensure that detent edge 30d maintains a firm engagement with tip edge 32.

The push button buckle of the invention will be seen to provide several advantages over the known buckles of this type. Since its overall construction is extremely simple, it may be economically manufactured. This economy of manufacture is abetted by the fact that all of the buckle parts may be readily and easily fabricated on a mass scale using known methods and machinery. The assembly of the several latch parts is also extremely simple, thereby minimizing the assembly time and further adding to the economy aspect of the buckle. For example, the several latch parts may be substantially entirely assembled-or disassembled-by hand by unskilled workmen. The invention latch also provides a low release effort under loaded conditions (for example, with an occupant suspended by the belt in an upside down position in an overturned vehicle)'since only one part is moved during the releasing operation and this part moves with an absolute minimum of friction. Specifically, only lever 30 moves during the releasing operation and this part rocks with an absolute minimum of frictional resistance because of the extremely small area of rocking contact of lever aperture corners 42a with the lower edge 38a of bar 38.

Although a preferred embodiment of the invention has been illustrated and described in detail, it will be apparent that various changes and modifications may be made in the disclosed embodiment without departing from the scope or spirit of the invention.

I claim:

1. A seat belt buckle comprising:

A. a housing assembly including a metal base member having a bottom wall and longitudinal side walls and a plastic cover member having a top wall overlying said base member and having side walls disposed in overlapping, outboard relation to said base member sidewalls;

B. a lever pivoted intermediate its ends within said housing assembly beneath said top wall for pivotal movement about a generally horizontal axis and defining a detent structure at one end thereof disposed adjacent one end of said housing assembly;

C. means on said housing assembly defining a horizontally disposed slot at said one end thereoffor passage of the tip end of the mating belt assembly for'coaction of said tip end with said detent structure;

D. means on said top wall defining a lever actuator area overlying the other end of said lever to permit depression of that lever end to release said detent structure from said tip end; and

E. a wire spring member of generally U configuration positioned within said housing assembly with the bight portion of the U engaging the underside of said other end of said lever to continuously bias that end upwardly and the legs of the U extending forwardly within the housing assembly and passing outwardly at their free ends through said base member sidewalls for engagement with said cover member sidewalls.

2. A seat belt buckle comprising:

A. a housing assembly including spaced top and bottom walls;

B. a lever pivoted intermediate its ends within said housing assembly between said top and bottom walls for pivotal movement about a generally horizontal axis and defining a detent structure at its forward end disposed adjacent the forward end of said housing assembly;

C. means on said housing assembly defining a horizontally disposed slot at said forward end thereof for passage of the tip end of the mating belt assembly for coaction of said tip end with said detent structure;

D. means on said top wall defining an opening therein overlying the rearward end of said lever to permit depression of that lever end to release said detent structure from said tip end; and

B. an insert member positioned within said housing assembly adjacent said forward end thereof and defining at cluding F. a rigid member positioned fixedly within said housing assembly in a position directly overlying the leading end portion of said tip end with the latter in its detented position to preclude upward tilting movement of said tip end. 4. A seat belt buckle according to claim 3 wherein G. said rigid member comprises a bar positioned fixedly within said housing assembly in a generally transverse orientation, said bar having an angular configuration in cross section and including a generally downwardly oriented leg portion and a generally horizontally oriented leg portion extending forwardly from the upper end of said downwardly oriented leg portion to directly overlie the rearward portion of said ramp surface and define therebetween a pocket receiving and restraining the leading edge portion of said tip end with the latter in its detented position; and H. said lever includes vertically disposed mounting portions having angular apertures passing said bar with a comer edge portion of each of said apertures having rocking engagement with the lower horizontal edge of said downwardly extending bar portion to define said pivot axis. 5. A seat belt buckle according to claim 4 wherein I. said housing assembly includes 1. a metal base member having a bottom wall and longitudinal sidewalls and 2. a molded plastic cover member overlying said base member to define said top wall of said housing assembly and having longitudinal sidewalls disposed in overlapping, outboard relation to said base member sidewall; and

J. said angular bar is slideably received in angular slots in said base member side walls whereby said bar may be readily inserted into or removed from said base member and is held in its assembled position by the cover member sidewalls.

6. A seat belt assembly according to claim 4 wherein l. the rearward end of said insert member includes a transversely extending groove seating said lower horizontal edge of said downwardly extending bar portion to preclude upward displacement of the insert member rearward end.

7. A seat belt assembly according to claim 2 wherein F. said insert member includes two generally longitudinally extending, upwardly opening grooves dividing said insert member into 1. a central portion between said grooves defining at its upper face said upwardly angled ramp surface and 2. two outrigger portions laterally flanking said central portion; said seat belt assembly further including 6. a wire spring member of generally U configuration positioned within said housing assembly with the bight portion of the U engaging the underside of said rearward lever end to continuously bias that end upwardly and the legs of the U extending forwardly within said grooves for anchoring engagement at their forward ends with said housing assembly. 8. A seat belt assembly according to claim 7 and further including H. a rigid member positioned fixedly within said housing assembly in a position directly overlying the leading end portion of said tip end with the latter in its detented position to preclude upward tilting movement of said tip end. A seat belt assembly according to claim 8 wherein said rigid member comprises a bar positioned fixedly within said housing assembly in a general] transverse orlentation, said bar having an angu ar con iguratlon in cross section and including a generally downwardly oriented leg portion and a generally horizontally oriented leg portion extending forwardly from the upper end of said downwardly oriented leg portion to directly overlie the rearward portion of said ramp surface and define therebetween a pocket receiving and restraining the leading edge portion of said tip end with the latter in its detented position;

J. said lever includes vertically disposed mounting portions having angular apertures passing said bar with a comer edge portion of each of said apertures having rocking engagement with the lower horizontal edge of said downwardly extending bar portion to define said pivot axis; and

l(.'said central portion of said insert member includes a transversely extending groove seating said lower horizontal edge of said downwardly extending bar portion-and said wire spring member includes knee portions interconnecting said bight portion and said leg portions, said knee portions dipping downwardly beneath said bar for pressing engagement with said housing assembly bottom wall at either side of said insert member central portion.

10. A seat belt buckle comprising:

A. a housing assembly including spaced top and bottom walls;

B. a lever pivoted intermediate its ends within said housing assembly between said top and bottom walls for pivotal movement about a generally horizontal axis and defining a detent structure at its forward end disposed adjacent the forward end of said housing assembly;

C. means on said housing assembly defining a horizontally disposed slot at said forward end thereof for passage of the tip end of the mating belt assembly for coaction of said tip end with said detent structure;

D. means on said top wall defining an opening therein overlying the rearward end of said lever to permit depression of that lever end to release said detent structure from said tip end; and

E. means positioned within said housing assembly adjacent said forward end thereof and defining a flat ramp surface angling upwardly relative to the general plane of said bottom wall from said forward housing assembly end toward the rearward housing assembly end with the plane of said ramp surface passing above the pivot axis of said lever. 

1. A seat belt buckle comprising: a. a housing assembly including a metal base member having a bottom wall and longitudinal side walls and a plastic cover member having a top wall overlying said base member and having side walls disposed in overlapping, outboard relation to said base member sidewalls; B. a lever pivoted intermediate its ends within said housing assembly beneath said top wall for pivotal movement about a generally horizontal axis and defining a detent structure at one end thereof disposed adjacent one end of said housing assembly; C. means on said housing assembly defining a horizontally disposed slot at said one end thereof for passage of the tip end of the mating belt assembly for coaction of said tip end with said detent structure; D. means on said top wall defiNing a lever actuator area overlying the other end of said lever to permit depression of that lever end to release said detent structure from said tip end; and E. a wire spring member of generally U configuration positioned within said housing assembly with the bight portion of the U engaging the underside of said other end of said lever to continuously bias that end upwardly and the legs of the U extending forwardly within the housing assembly and passing outwardly at their free ends through said base member sidewalls for engagement with said cover member sidewalls.
 2. A seat belt buckle comprising: A. a housing assembly including spaced top and bottom walls; B. a lever pivoted intermediate its ends within said housing assembly between said top and bottom walls for pivotal movement about a generally horizontal axis and defining a detent structure at its forward end disposed adjacent the forward end of said housing assembly; C. means on said housing assembly defining a horizontally disposed slot at said forward end thereof for passage of the tip end of the mating belt assembly for coaction of said tip end with said detent structure; D. means on said top wall defining an opening therein overlying the rearward end of said lever to permit depression of that lever end to release said detent structure from said tip end; and E. an insert member positioned within said housing assembly adjacent said forward end thereof and defining at its upper face a flat ramp surface angling upwardly relative to the general plane of said bottom wall from said forward housing assembly end toward the rearward housing assembly end with the plane of said ramp surface passing above the pivot axis of said lever.
 2. two outrigger portions laterally flanking said central portion; said seat belt assembly further including G. a wire spring member of generally U configuration positioned within said housing assembly with the bight portion of the U engaging the underside of said rearward lever end to continuously bias that end upwardly and the legs of the U extending forwardly within said grooves for anchoring engagement at their forward ends with said housing assembly.
 2. a molded plastic cover member overlying said base member to define said top wall of said housing assembly and having longitudinal sidewalls disposed in overlapping, outboard relation to said base member sidewall; and J. said angular bar is slideably received in angular slots in said base member side walls whereby said bar may be readily inserted into or removed from said base member and is held in its assembled position by the cover member sidewalls.
 3. A seat belt buckle according to claim 2 and further including F. a rigid member positioned fixedly within said housing assembly in a position directly overlying the leading end portion of said tip end with the latter in its detented position to preclude upward tilting movement of said tip end.
 4. A seat belt buckle according to claim 3 wherein G. said rigid member comprises a bar positioned fixedly within said housing assembly in a generally transverse orientation, said bar having an angular configuration in cross section and including a generally downwardly oriented leg portion and a generally horizontally oriented leg portion extending forwardly from the upper end of said downwardly oriented leg portion to directly overlie the rearward portion of said ramp surface and define therebetween a pocket receiving and restraining the leading edge portion of said tip end with the latter in its detented position; and H. said lever includes vertically disposed mounting portions having angular apertures passing said bar with a corner edge portion of each of said apertures having rocking engagement with the lower horizontal edge of said downwardly extending bar portion to define said pivot axis.
 5. A seat belt buckle according to claim 4 wherein I. said housing assembly includes
 6. A seat belt assembly according to claim 4 wherein I. the rearward end of said insert member includes a transversely extending groove seating said lower horizontal edge of said downwardly extending bar portion to preclude upward displacement of the insert member rearward end.
 7. A seat belt assembly according to claim 2 wherein F. said insert member includes two generally loNgitudinally extending, upwardly opening grooves dividing said insert member into
 8. A seat belt assembly according to claim 7 and further including H. a rigid member positioned fixedly within said housing assembly in a position directly overlying the leading end portion of said tip end with the latter in its detented position to preclude upward tilting movement of said tip end.
 9. A seat belt assembly according to claim 8 wherein I. said rigid member comprises a bar positioned fixedly within said housing assembly in a generally transverse orientation, said bar having an angular configuration in cross section and including a generally downwardly oriented leg portion and a generally horizontally oriented leg portion extending forwardly from the upper end of said downwardly oriented leg portion to directly overlie the rearward portion of said ramp surface and define therebetween a pocket receiving and restraining the leading edge portion of said tip end with the latter in its detented position; J. said lever includes vertically disposed mounting portions having angular apertures passing said bar with a corner edge portion of each of said apertures having rocking engagement with the lower horizontal edge of said downwardly extending bar portion to define said pivot axis; and K. said central portion of said insert member includes a transversely extending groove seating said lower horizontal edge of said downwardly extending bar portion and said wire spring member includes knee portions interconnecting said bight portion and said leg portions, said knee portions dipping downwardly beneath said bar for pressing engagement with said housing assembly bottom wall at either side of said insert member central portion.
 10. A seat belt buckle comprising: A. a housing assembly including spaced top and bottom walls; B. a lever pivoted intermediate its ends within said housing assembly between said top and bottom walls for pivotal movement about a generally horizontal axis and defining a detent structure at its forward end disposed adjacent the forward end of said housing assembly; C. means on said housing assembly defining a horizontally disposed slot at said forward end thereof for passage of the tip end of the mating belt assembly for coaction of said tip end with said detent structure; D. means on said top wall defining an opening therein overlying the rearward end of said lever to permit depression of that lever end to release said detent structure from said tip end; and E. means positioned within said housing assembly adjacent said forward end thereof and defining a flat ramp surface angling upwardly relative to the general plane of said bottom wall from said forward housing assembly end toward the rearward housing assembly end with the plane of said ramp surface passing above the pivot axis of said lever. 